Chembio Diagnostics Inc. has won regulatory approval to sell its rapid test for Zika and a companion results reader in Brazil, the country hit hardest by the mosquito-borne virus, executives said.

The Medford-based maker of point-of-care tests for HIV, syphilis and tropical diseases said last week its results reader has been approved for commercial sale by the Brazilian health regulator Agencia Nacional de Vigilancia Sanitaria.

Brazil is the epicenter of the Zika virus, which causes the birth defect microcephaly where infants have smaller-than-normal heads. More than 2,300 cases have been confirmed in the South American country, and over 3,000 cases are being investigated.

Chembio developed its testing system with Bio-Manguinhos/Fiocruz, a unit of the Oswaldo Cruz Foundation, the Brazilian-government agency responsible for producing tests, vaccines and drugs for use by the public health system.